This part is a kind of semiconductor called BTB04-600.

Function of this product has 4A TRIACS.

Manufacturers : TGS

Image and pinout :

Some of the text within the PDF file :

TIGER ELECTRONICProduct CO.,LTD specification 4A TRIACS GENERAL DESCRIPTION Available either in through-hole or surface-mount packages, the BTA/BTB04 - 600 triac series is suitable for general purpose AC switching. They can be used as an ON/OFF function in applications such as static relays, heating regulation, induction motor starting circuits... or for phase control operation in light dimmers, motor speed controllers, ... The snubberless versions (BTA/BTB...W series) are specially recommended for use on inductive loads, thanks to their high commutation performances. By using an internal ceramic pad, the BTA series provides voltage insulated tab (rated at 2500V RMS) complying with UL standards. BTA/BTB04-600 ABSOLUTE MAXIMUM RATINGS ( Ta = 25 C) PARAMETER Repetitive peak off-state volta [ ... ]

BTB04-600 PDF Datasheet Download